Valverde was among the best relievers in baseball with the Arizona Diamondbacks, Houston Astros and Detroit Tigers. He led the league in saves three times in a span of five years (2007-11), including a career-high 49 in 2011 with Detroit.

His last solid season came in 2012, when he registered 35 saves for the Tigers, but he struggled over the following two seasons. Valverde signed a minor-league deal contract with Washington in April after opting out of a similar deal with San Diego. He was released by the Nationals on July 22.

Valverde amassed 288 career saves while posting a 27-33 record and 3.27 ERA over 12 seasons with four clubs.